SLAA475A October 2010 – March 2019 MSP430L092
The APINT counter starts at the current APINT value and counts either up or down, depending on the status of the SLOPE bit. When the comparator output signal changes, an end-of-conversion signal is generated and can be used to stop the counter (see Figure 5). The value in the APINT register is then the measured value of the input signal. When using the ramp generator method, four different methods are possible to recalculate internal offsets and errors that are coming from the A-Pool module itself. For example, the comparator has always a little offset, which can create either higher or lower result values. In addition, an overdrive error can occur out of the internal logic of the A-Pool. With a high A-Pool input frequency, the module might not react fast enough to stop the counter correctly.